Fiber optic cable with external iron sheath

Fiber optic cables with external metallic sheaths, such as steel tape or corrugated steel tape (CST) armored cables, provide mechanical protection, rodent resistance, and suitability for outdoor or underground installations.

Construction and Sheathing Types

Fiber optic cables designed for harsh environments often include a metallic armor layer to protect the fragile optical fibers inside. Common constructions include:

• Steel Tape Armored (STA): A layer of steel tape wrapped around the cable core, providing crush resistance and protection against physical damage, suitable for direct burial or duct installations .
• Corrugated Steel Tape (CST) Armored: Features a corrugated steel tape for enhanced mechanical strength, rodent protection, and flexibility for outdoor or industrial environments. CST cables are often combined with a double polyethylene (PE) sheath for water and chemical resistance .
• Single Sheath Metallic Armor: Combines steel tape armoring with a protective outer jacket, often polyethylene, for underground or duct deployment, supporting both pulling and air-assisted blowing installation methods .

Inside the metallic sheath, cables typically use a loose tube design with optical fibers protected by glass yarn strength members and water-blocking elements, ensuring durability and long-term performance .

Applications

These armored fiber optic cables are ideal for:

• Outdoor and external installations exposed to mechanical stress or environmental hazards
• Direct burial in trenches or underground ducts
• Industrial sites and campus networks requiring high crush and rodent resistance
• High-speed data transmission for backbone networks, Ethernet, and data center interconnects .

Advantages

• Mechanical protection against crushing, impact, and bending
• Rodent resistance due to steel armor
• Environmental durability with PE or LSZH outer jackets
• Ease of installation in ducts or direct burial scenarios
• Compliance with safety standards such as IEC 60332-1, IEC 61034, and IEC 60754 for low smoke and halogen-free materials .

Summary

Fiber optic cables with an external iron or metallic sheath, such as steel tape or CST armored cables, are specifically engineered for harsh outdoor, underground, or industrial environments. They combine mechanical strength, environmental protection, and reliable optical performance, making them suitable for high-speed data networks where durability and long-term reliability are critical .